A Little Spill - My First Pinecest FanFic WIP
by theJalden
Summary: The events in this book take place 5 years after the events in the show. Dipper an Mabel are back in Gravity Falls for their last Summer together before college. After rummaging through some of their old stuff they find an old love potion. It breaks and gets all over the twins, but nothing can break the relationship these guys have. Right? There will be more.
1. Chapter 1

Chapter 1 - Oops:

"Mabel, look, I've found it!" Dipper pulled out the grappling hook his sister received as a gift on their first day in Gravity Falls five years ago. "Man, remember how you totally saved my life with this?"

"Yeah, I'm pretty awesome, aren't I?" Mabel replied.

"You can say that again," said Dipper.

"I'm pretty awesome, aren't I? _phltpht_." She stuck out her tongue and blew a raspberry. "I was only able to save both of us, after you single handedly defeated Gideon." As she mentioned the fight, she mimed some punches, finishing with an uppercut to her imagined Gideon's chin.

"Here Dip, hand it over, I want to see if I've still got it." Dipper tossed her the grappling hook, and with it, she took careful aim at the crossbar in the ceiling. She fired, and the hook bounced off the bar and squarely hit a ceramic lamp, breaking it into a dozen pieces.

"GRAPPLING HOOK!" Mabel shouted, holding up the tool above her head triumphantly.

Dipper and Mabel were back in Gravity Falls after 5 years. _The Mystery Twins back in action_, thought Dipper. He and Mabel were staying with their great uncle in Gravity Falls, Oregon. Gruncle Stan still lived in the Mystery Shack. The "S" on the sign had long since fallen down, giving a more apt description of both the place and the man who owned it.

The last time they were in Gravity Falls they stayed the whole summer. This visit, they were only staying one week. And right now, they were going through some old stuff their Gruncle kept from their last visit.

"Hey Dip, I found some glittery stuff. It says Love Potion. _Gasp._ This must be the love potion I got from the Love God." Mabel's eye went wide at the thought of playing matchmaker again.

"Don't you mean stole?" asked Dipper. "That's the stuff you used on Robbie and Tambry, right? I wonder if they're still together?"

"I don't know, you should ask Wendy. I invited her over to a sleepover tonight," said Mabel.

"Ugh, you mean putting on makeup, watching cheesy movies and talking about boys all night? Count me out," said Dipper.

"You make it sound like those are bad things."

Dipper rolled his eyes. "Back on the Love Potion, I thought you got rid of that stuff ages ago."

"Yeah, well, I didn't." Mabel giggled at her naughtiness, and held up the bottle in front of her face. "A gift from the gods should never be turned away lightly. See for yourself." Mabel tossed the flask over to Dipper, who was not expecting it.

"Wait, wha-" was all Dipper was able to say. The time seemed to move more slowly to him. He tried to catch the flask but it just bounced out of his clumsy hands. He tried once more to catch it on the rebound with his left, but it just bounced out again. Dipper reached out again with his right, but the flask would not be caught. It fell forward, and Dipper swiped absurdly at it, trying to stop it from falling, but it landed, and broke on the floor.

A giant cloud of pink dust filled the room for a couple of seconds. After Dipper and Mabel stopped coughing, they looked around, then at each other. Dipper started talking first.

"I'm, uh, sorry I didn't catch that." Dipper said, trailing off at the end and looking down at his shoes. _Oh boy. Am I in love with my sister now? What if she's in love with me? Stupid hands, why can't you catch anything?_

"Yeah, well, I probably shouldn't have thrown it to you when you weren't looking," she said in her actually-being-serious voice.

_Ok Dipper, just look at your sister, and assess your feelings._ Dipper looked up at his sister, and saw… his sister. Same as she was standing there a few minutes ago, only looking down and to the side. She was wearing one of her trademark sweaters, with a question mark symbol to signify her return to the Mystery Shack. He remembered watching cartoons with her in the mornings, and racing back home from school. He remembered normal brother and sister stuff. _This is Mabel, she is my twin sister, I don't feel anything romantic._ Yet, Mabel was still visibly upset.

Dipper walked over to her and placed a hand on her shoulder. "Look, Mabes, it's fine, I don't think the love potion did anything. Look, I don't feel any different. How about you?"

Mabel looked at Dipper, then looked right into his eyes, and held the gaze for a second. "No. No, I suppose I don't, broseph." Mabel, lightly punched Dipper's hand off her shoulder, and seemed to cheer up a little, a grin returning to her face.

"Yeah, it's like, we're twins right, so we already have the strongest love possible, it's not like a dumb potion could change that. Right?" asked Dipper.

"Right. But we should probably clean this up before anyone notices." Said Mabel.

"Right."

Dipper followed Mabel down the stairs, and noticed that she smelled good today. Not just average good, but really good. _Why am I noticing her smell? You never noticed it before. Nothing good can come from this line of thought. Nope, never happened, you didn't smell your sister._ Dipper breathed through his mouth the rest of the way down.


	2. Chapter 2

Sleep Over:

Mabel had wasted no time reacquainting with her old friends. That night she hosted a sleepover at the Mystery Shack, and invited Candy, Grenda, and Wendy. "Thanks for coming guys you have no idea how long I've wanted to see you again." Mabel squealed.

"The feeling is definitely mutual," said Candy.

"Dude, dude, I have so much stuff to tell you about college, like you wouldn't even believe," said Wendy.

"Sister, I discovered a conspiracy to cover up the eighth and a half president of the United States, college would have to be pretty fantastic," said Mabel.

"Oh, don't worry, it is," said Wendy. "Hey, where's Dipper, I want to say hi to that little dork."

"I think he's downstairs watching movies with Soos."

"No way, Soos is here too, man it's just like old times."

"Yeah, I'll get them." Mabel turned towards the stairway. "DIPPER, SOOS, GET YOUR BUTTS UP HERE, PEOPLE WANT TO SEE YOU!" Dipper seemed to be avoiding Mabel since the accident with the love potion that afternoon. _He's probably just a little weirded out. I know I was._

At first Mabel thought she might have fallen in love with her little bro, but she didn't feel anything around Dipper that was like her previous crushes. There was no swooning, or butterflies in her stomach. When she looked at him she saw her adorable, paranoid dork of a brother. That wasn't to say that things were normal between them. Things seemed a little more awkward in forced, even in the few hours since the incident.

Some movement was heard at the base of the stairs. Dipper came up dressed in his ever-present flannel shirt, jeans, and blue and white Gravity Falls cap. Soos followed wearing a solid blue t-shirt and cargo shorts.

"Hey, uh, what's up dudes?" Asked Soos.

"Hi Candy, Grenda. Hello Wendy." Dipper shook each of their hands and gave Wendy a fist bump. "Oh Wendy, how are Robbie and Tambry doing?"

"Come on dude, it's been five years and the first thing you ask me is about those two losers. Where's the, "How's it going, Wendy?"."

"Sorry, that was from a previous discussion." Dipper glanced at Mabel and then back at Wendy. "How's it going, then?"

Mabel saw Wendy change posture, like she was trying to look cool. And she saw they way Wendy turned a slight shade of pink as she looked over Dipper. _Oh my god, Wendy likes Dipper._ Mabel felt like she didn't like it.

"Fantastic, thanks for asking." Said Wendy, "I'm majoring in biology and doing research with this gene splicing place. I'm going to help develop a super fast growing tree and revolutionize the logging industry. Oh, and Robbie and Tambry are still together, they're even living together. I'll bet they even get married soon. And it's all because of our local match-maker Mabel." Wendy gave a thumbs up to Mabel, who hesitantly returned it.

"Really? That's so cool! The gene splicing thing I mean, not the Robbie thing. I mean, that's cool too," replied Dipper, "I was thinking of majoring in cryptography when I get into college. Codes and ciphers always fascinated me."

"I know you broke one Cipher pretty good already." Said Wendy, referring to the demonic one-eyed triangle, Bill Cipher.

Wendy smiled at Dipper, and held it for a few seconds. Dipper returned the smile, not knowing what to say. They held that position in awkward silence for what seemed like two seconds of eternity.

"All right, that's enough, girl time now." Said Mabel, trying to break up whatever was going on. "We still need to do make overs and watch 80's movies." She looked back at Dipper and furrowed her brow. This night wasn't supposed to be about him.

They all went up to the attic room. "Okay ladies, who wants a Mabe-over?" She started chanting "Mabe-over! Mabe-over! Mabe-over!" And the rest joined in.

After they had all gotten their foundation on, Wendy started talking. "Okay, so are we not going to talk about how hot Dipper has become?"

"Oh yeah, what a cutie." Said Grenda.

"Come on guys, wouldn't you rather talk about Ryan Gosling, or Harry Styles from One Direction? Or, you know someone who isn't my dorky brother," said Mabel.

"Come on Mabel, lighten up. I get that he's your brother and all, but he's like right here." Said Wendy. She turned to face the other girls, and said. "Okay, you know how Dipper had this obvious crush on me the last time he was here? Well, let's just say, now it might be the other way around."

"Blargh!" said Mabel. "Don't be gross."

"No, it's okay, I did the math. I'm 21 right, and the youngest you are allowed to date is half your age plus 7, Dipper's almost 18 so it's totally not weird." Said Wendy.

"Not if I get him first." Candy tittered. "Oh, he is so smart, and brave. You know how many times he saved you Mabel, he is just like a knight in sparkling armor, I'd always feel safe with him. He and I would rule the world together." Candy giggle maniacally.

Mabel couldn't help but to remember all the times Dipper came in to protect her. Pulling her aside just in time to not get hit by a rouge projectile. Sacrificing winning Wendy the toy at the carnival just so she could have Waddles. And saving her from a giant robotic Gideon. It was true, Dipper was smart, and brave and all those other things. And he was even hot.

Mabel thought about Dipper coming out of the shower back home. He wasn't like super muscular or anything like that. But he had a lean, taught frame. He joined track and field and was a decent mid to long distance runner. He was also tall. In the past few years, he had blown right past her height-wise. While she was an average five-foot-seven, Dipper was an even six feet tall. He really was the alpha twin.

She let herself wonder, briefly, what it would be like to kiss Dipper, lightly, on the lips. _Hold it right there girl! These are very un-sisterly thoughts you are having right now. It's just the love potion poisoning your mind. Quick! Change the subject._ "So, Wendy, tell us, what is college like?" Mabel asked, trying to sound like she was just moving the conversation along, and not like she was super weirded out by all of it. And she hoped that the blush she was applying now would conceal any actual blush she felt on her burning cheeks.

Wendy, perhaps noticing Mabel's discomfort about the conversation, obliged and started talking about her many adventures at the University of Oregon.


	3. Chapter 3

Meanwhile:

Meanwhile, Dipper was trying his best to act like everything was cool. Over the course of the day he had been noticing things about his sister that no brother should. Like the way her hips moved as she walked , how smooth her legs were, and how her sweater rested on her small and perky bosom. Each time he saw her, like that, he casually reminded himself that what he though was the work of the potion screwing with his mind. _This is Mabel, she is my twin sister. I don't feel anything romantic towards her. I can't feel anything romantic towards her, that would be as wrong as it gets._

Currently, Dipper was with Soos in the basement, watching really bad mystery movies. Dipper had long since solved the mystery and was only half-watching it now.

"Hey dude, did you see how Wendy looked at you when you walked up. I think she likes what she sees," said Soos.

"No way, man. Wendy and I are just friends, she was probably just happy to see me after all this time," said Dipper.

"Whatever you say man, but if you ask me, I say you couldn't do better than Wendy."

And image of Mabel dancing to pop music in her room came into Dipper's head. _No, bad brain, think of something else._ "Hey Soos, how are things with you and Melody?"

"We, uh, we kind of broke up a few years ago. It was difficult keeping up the long distance relationship, and we both wanted different things. It was for the best."

"Geeze, sorry, I didn't know."

"That's why you had to ask. And don't be sorry, it was totally mutual. Also, I found someone else. Her name's Sara, and she completes me. She likes to cook and I like to eat. She's good at breaking things, and I'm good at fixing them, it just feels right. You should really think of getting together with someone like that."

Dipper's mind, predictably went straight back to Mabel. _She's like the perfect Yin to my Yang._ Mabel was fantastically artistic where he could barely draw a straight line. She could couldn't divide two numbers, where as he could integrate like a champion. Dipper preferred solitude, and Mabel was the dictionary definition of an extrovert. Where Dipper was cunning and logical, Mabel could think of fantastic ideas right on the fly. _What the hell are you thinking Dipper? Bad, no thinking of her like this. Quick change the subject._

"Hey, do you know when Gruncle Stan gets back?" Dipper asked.

"He said he would be back around done around nine, so we still got a few hours. Really stinks that he wasn't around when you got back." Soos reached over the back of the chair and pulled out a can of beer. "Hey Dip, how would you like one of these?" said Soos.

"Soos, you know I'm underage, right?" said Dipper.

"Yeah, well, you need to have your first beer at some time, why not with your best buddy Soos? And Gruncle Stand doesn't have to know."

Dipper reluctantly agreed. He opened up the can and took a quick sip. It tasted so bitter that he spit it out immediately. "Bleh, this tastes aweful. How can anyone stand it."

"You don't drink it for the taste, dude. You just kind of drink it and it makes you feel good."

After the first beer Dipper noticed that the movie was interesting again. Dipper explained to Soos who the murderer was, and how he pulled it off. And he even got excited when the detective revealed who did it. "Yes! I was right. No one solves a mystery like the Dip." Dipper was halfway through with his second can of beer when the movie ended.

_This isn't bad, I get why everybody drinks this stuff._ "Hey, Soos, can I ask you something?" _Wait am I going to tell him about this morning? Does he really need to know?_ Dipper was feeling slightly light headed, and found conversation was coming easier to him. Maybe too easily.

"Sure dude, Tell Dr. Soos whatever you need to get off your chest."

Dipper laughed at Soos's inadvertent pun. "Dude, you just called yourself Dr. Soos. Like the guy who wrote "The Cat in the Hat"."

"Oh, ha ha, yeah, that's pretty funny."

Dipper recomposed himself. "Ok earlier this morning I had an accident, in the attic with Mabel."

"Did you fart in front of her. Once I farted in front of a girl at a party, and she yelled at me. That wasn't a very fun time."

"No, it wasn't that," said Dipper. "We were going over some old stuff, and she found a love potion, and then she threw it at me, and I dropped it. And it got all over the place. And now, I kind of might be thinking thoughts about her that I shouldn't." Dipper cringed as he said those last words. _Why did you just say that, you can handle it yourself, no one needs to know. _But it was said. Dipper thought that vocalizing the thoughts he had been beating back all day made it too real. The alcohol helped him push through it, and he took a large sip.

"Please don't tell Mabel, she'd think I'm some kind of monster. And not the kind she likes," said Dipper.

"Wow, that's heavy man, I wish I knew how to help you," said Soos. " I've never gone through what you are now, being an only child and all. Normally I would say follow your heart, but that doesn't seem like the right choice in this scenario."

Dipper took another sip. "Okay, but how do I stop it. I don't want to be thinking of my sister in that way. Nothing good can come out of it."

"Okay, I get you dude," said Soos. "Well in my experience the worst thing you can do is to suppress it and beat yourself up for thinking about it. You should be like the Buddhist monks when they meditate, you just let yourself think normally, and if you find yourself thinking about your sister just acknowledge the thought for what it is, fold it up, and throw it away."

"Thanks Soos, that was actually really wise. I feel-." Dipper felt a pressure building in his bladder. "I feel like I really need to use the bathroom." Dipper ran back upstairs to relive himself.

As he was going upstairs he heard Soos calling back. "Yeah, beer will do that to you. Good luck dude!"


	4. Chapter 4

AN: This Chapter got a little out of hand. Hope you like it despite the length.

Dreams:

It took a while but at last everyone was asleep. After Wendy finished telling everyone how cool college was, what she learned and all the really neat people she met, they watched "80s Dream Boy High School 3," Mable's personal favorite of all the Dream Boy movies.

She felt more secure underneath her covers; she felt that she could express her own thoughts to herself. _Okay, let's go over the events one more time. First I tossed the potion to Dipper, then he dropped it. Then I thought I might be suddenly in love with him, and I wasn't. Then things were cool, and now they aren't. Ugh, Wendy, why did you have to bring him up?_ Now all Mabel could think of was Dipper. She imagined him holding her in his arms, and rocking her back and forth, and whispering her name to her.

When they were kids, if Mabel had a nightmare she would always go to Dipper's room, and he would always let her sleep next to him for the rest of the night. Now it was just as scary, but it wasn't a dream, and she couldn't go to Dipper. _Cut the crap, Mabel!_ Shouted a voice in her head. _You've let Dipper get under your skin. You are a soldier, you are strong, and you are not in love with your brother._ Mabel snapped to attention. The little drill sergent in her head was right. She put on her trying-to-be-serious face and focused on not thinking about Dipper.

She spread herself out in her bed and said to herself, _okay, Mabel. Sleep!_ But she was still awake. She was able to hear Grenda starting to snore, and the others breathing deeply. _Ugh, this is going to be a long night._

Dipper was drifting to sleep in the guest bedroom. For a while he tried the Buddhist meditation thing, but the alcohol was messing with his head. He was acknowledging the thoughts well enough, but he was having trouble discarding them. It wasn't long until he was erect, and it wasn't much longer after that his hand crept down beneath the sheets, beneath the elastic waistband of his boxers, and started fondling his junk. He was thinking of Mabel coming down on him, and taking his entire penis in her mouth.

Suddenly alarm bells went off in Dipper's head. _Wait, no way can you do this. Masturbating to your sister crosses like, 14 lines that should not be crossed._ Dipper rolled onto his stomach and put his hands under the pillow. _Bad hands, you aren't coming out until you think about what you have done._

Dipper felt guilty. Earlier he had told Mabel that the love potion didn't affect him, and he supposed that at the time it was true, but now he was restraining himself from masturbating to her. It was kind of a sad sight. _Remember, you are not in love with your sister. Whatever you feel, it's the potion. You can't have romantic feelings towards your sister, it's just wrong._

After what felt like forever, sleep eventually found Mabel. Everything started off fairly normally. She was Lady Mabelton, ruler over Mabelland and of its people. Waddles the pig was wearing a full suit of armor. He announced the first order of business. "The pastry and the candy clans have been feuding for generations over which one of them is the most delicious. They ask you, wise and beautiful Lady Mabelton to settle the debate once and for all."

"Send forth a representative from each party."

A giant anthropomorphic slice of chocolate cake and lollipop stepped forward and genuflected. "Please rise," said Lady Mabelton. "You come before me today to settle a feud which has lasted thousands of years. Which is more delicious; candy, or pastry. To settle the matter I have asked you to prepare a representative dish for me to sample."

"Yes, your majesty, that is correct," said the Lollipop. "My people have created the finest chocolate blend for you. In it you will find swirls of white chocolate, chunks of nougat, and small bits of marshmallow."

Mabel took one bite. It was the best thing she ever tasted. She wanted to cry for how sweet it was. But she kept her composure, as any good queen should. "Thank you Lord Lolli, and you." She said, gesturing toward the chocolate cake.

"Your majesty. The most noted chefs in the land slaved for weeks over the kitchen, not resting until everything was perfect. For you a bring a strawberry cupcake, topped with butterscotch frosting and chocolate shavings, and filled with a light custard."

Mabel took a bite of the pastry, and it was just a tasty as the candy. How could she judge when both were just as delicious. If she said she preferred neither, they would continue to fight as they had for generations.

"I make my final verdict. Lord Lolli, your chocolate was by far and away the best candy to have graced my mouth. But I must give favor to Baron von Chocolate. The pastry is just able to layer flavor in a way candy cannot match. But you two shouldn't be fighting. You are both masters of your craft, you should be working together to create the greatest treat that has ever been made in the history of the universe."

Lord Lolli was visibly disappointed, but he kept a smile and said to Baron von Chocolate, "You win fair and square, perhaps now we should bring our tribes together. If the Lady Mabelton wills it, then I will it too."

Baron von Chocolate agreed, and the two walked out of the grand hall holding hands. Mabel felt smug for doing her part to bring peace to the kingdom.

Waddles announced, "Next order of business, there is a suitor here to meet you."

"Bring him in for me to meet," said Mabel.

The large double doors at the front of the court opened up, and in rid an elegant knight wearing full plate armor, and sparkled in the sunlight streaming through the open doors. His mount was a mare with a fine white coat, specks of grey flecked the horse's nose and rear.

"Introducing, Lord Dippinsauce, the Brave," said Waddles.

The knight took off his helmet and underneath was Dipper, grinning a crooked smile. He rode up to the throne with his helmet under one arm. He reached out his other arm, and said "Lady Mabelton, would you come with me?"

Mabel took the knight's hand and mounted the horse behind him. The two rode back out though the double doors. Dipper and Mabel rode through the city, past the gates, and though the country side. All the way Mabel held onto her brave knight, feeling him move back and forth to the rhythm of the horse. Dipper was solid. When he was there Mabel didn't need anyone else.

Out of nowhere a bandit with a black mask jumped in front of them. "Give me Lady Mabelton, the most beautiful princess in all the Kingdom, and I'll let you live." The bandid held a bow and arrow, and aimed it at Dipper's head.

Mabel held on more tightly to Dipper. She heard Dipper say, "How about a third option?" Dipper charged forward with his horse, knocking the weapon out of his hand. Dipper then dismounted the horse, and tied the bandit to a nearby tree, leaving him for the police to find.

They started off again, and reached a field, with a small hill. On the hill. Dipper placed a blanket down and laid Mabel down on it, to face the setting sun. It was then that he place one arm on either side of her, leaned down, and kissed her. Dipper kissed Mabel with confidence. He was assertive, but not forceful. At every moment Mabel felt like she belonged only where she was. He smelled like a combination of sweat, pine trees, and a unique Dipper smell.

The kissing got more passionate, tongues were now involved. Dipper was moving his tongue around hers, like they were dancing in her mouth. Meanwhile his hand started stroking up and down her outer leg. Each stroke went just a little bit higher, and a little less outer until he was stroking around some very naughty places. Mabel didn't care, she only felt the ecstasy of the situation.

"Oh, yes, yes Dipper!" Mabel called out. And then she woke up with a start. _Did I just say that out loud?_ Mabel looked around, but she couldn't see much in the dark room. She listened and heard the deep breathing of the three other girls in the room. _Holy moly, girl. You were just having a sexy dream staring your bro bro._ Mabel decided that she definitely maybe did feel feelings about her brother. A little, it was nothing serious, like a half crush, or probably less. Definitely less, it was a crush so small you couldn't even see it.

Besides, even if she did feel something about her brother, a point which was highly debatable. It was just the potion was making her feel that way.

Dipper had also finally gotten to sleep. He had refused to allow his hands out from under the pillow, so sleeping was pretty much his only option. He dreamed that was he back in school.

He was walking to math class. Once he arrived, he stepped in, and the only person inside was his sister Mabel, doing homework.

When Dipper stepped in Mabel's face lit up. She said, "Dipper, you're a giant nerd, can you help me with my math?"

"Sure Mabes, but I can only guide you to the answer, you have to do the work yourself. Now what's the problem?" asked Dipper. Mabel was always asking for help with her homework. And somehow, despite his best efforts, it was Dipper who would always do it for her.

"Alright, there's this equation, and trig thingies. And I need to solve for x."

Dipper glanced at the problem and said, "Okay Mabel, this doesn't look that hard. The first step is to get everything in terms of the same trig function. Do you know what tangent is in relation to sine and cosine."

"I don't know. Ugh, I'm too hot now, I'm just going to take off my sweater," said Mabel. She grabbed her sweater and pulled it over her head. Underneath she wore nothing but a push-up bra. Her stomach was pale and toned, despite eating a diet of nearly pure sugar, which according to her counted as vegetarian.

"Well," said Dipper. "This is happening."

"You bet your butt it is. _Heh heh_. Honk!" Mabel gave a quick squeeze to Dipper's left ass cheek. Dipper stepped out of arms length. "Okay, tangent is sine over cosine, now what do I do?"

"That's right. Okay, I guess the less clothes thing is actually working. Well now, let's look at the different terms in the equation, you have a tangent squared times cosine and a sine, and on the other side you've got a cosine. What do you need to do in order to get all of them in terms of the same function."

"I don't know what you're even saying, it's like you're speaking a different language. Can't you just tell me?"

"No Mabel, I told you, I'm not giving you answers. You need to figure this out yourself."

"Well, what if I take off my skirt?"

"What if you-? Take it off, I don't care, I'm not doing your homework for you."

Mabel proceeded to unbutton her skirt and roll it down her legs. Dipper was captivated. Her legs started at her hip and they seemed to just keep going. Eventually they finally hit feet, but not until after a sensuous journey around her knees, and all around her calves. She was wearing pink panties, to match her bra, and her ass was shaped magnificently. Dipper licked his lips sub consciously.

"I can just divide everything by cosine x, then it will all be tangents," said Mabel.

Dipper looked up from gawking at his nearly naked sister. "Uh yeah, that was right again."

"Now what?" asked Mabel?

"Now what indeed." Said Dipper, focusing on how clear and smooth the skin of his sister was.

"Um, I need to solve for x, right, so I can just take the arctangent of both sides."

Distracted by the math error, Dipper said, "Not, exactly. To use the arctangent to get x, the equation needs to be solved in terms of the tangent of x. Here, there's something called u substitution. You basically say, u is equal to the tangent of x, then plug u in for tangent, and then solve for u."

"But how can I put u in there, this isn't a u in the problem."

"No, Mabel, you make it up, and solve for u."

"Why can't I just make up x and have the problem be solved then?"

Dipper was dumfounded. "Okay Mabel, each time you take off an article of clothing you get better at math. Just take off your bra, then you'll understand."

"Oh, I understand, you scallywag." Mabel winked at Dipper, then undid her bra. Which was almost too much for Dipper. Mabel's breasts were perky and the nipples were a rosy shade of pink. She looked up at Dipper and asked, "Is this better?"

"Huh?" Dipper asked stupidly.

"Is this math equation better. Dipper looked at the sheet, everything seemed right. "Yeah, this looks better, and this is basically a quadratic function now. You know how to solve it right?"

"Of course, I just plug it into the quadratic formula, negative b plus or minus the square root of b squared minus 4 a c, all over two a." She sang the formula to the tune of pop goes the weasel. Dipper was slightly disappointed that she didn't need to take off her last garment of clothing to solve it.

"Great job," said Dipper. "Now you know what u equals, what do you do now?"

"Substitute tangent of x back in and take the arc tangent of both sides!" Mabel exclaimed.

"Yes! Exactly, you've finally got it."

"All thank's to you bro bro." Mabel got up and hugged Dipper. Dipper was very uncomfortable about his naked-except-for-her-panties sister hugging him so intimately. But still, he welcomed the advance.

"It looks like Little Dipper is happy for me too." Mabel placed her hand in between Dippers legs and started rubbing his shaft, which had been hard since she divided by cosine. She kissed his cheek, and whispered into his ear. "I want you Dipper."

Dipper stammered back, "Y-Yeah?" and he started unbuttoning his shirt.

"Wait, first I need to find the answer." Mabel scribbled down a few lines and circled her answer.

Dipper looked over the answer, but saw it wasn't exactly right. "Okay, this is mostly right, but this answer doesn't work so you have to cancel it."

"Wait, why, the expression is 0 if x is equal to that, so shouldn't it work."

"Well, yes it should, but remember earlier, you divided by cosine, so you have to ignore everywhere that cosine is zero. Otherwise you divided by zero and your answer is wrong."

"So you're telling me you can't divide by zero?"

"Of course you can't." Dipper facepalmed. "That's like one of the first things you learn in math." Dipper drew a graph on the chalkboard with two bowing lines opposite each other, nearly touching the axes. "This is the graph of y equals one over x. You'll notice that as you get closer to zero, the line gets higher and higher on this side, and lower on lower on the other side. But they never actually reach the point where the graph is zero."

"But it was just going to be zero anyways, so wouldn't the zeros cancel out?"

"Well, zero divided by zero can be defined, it just isn't determinable. In fact, they invented an entire branch of mathematics devoted to finding out ways to express zero over zero, it's called calculus."

Dipper started explaining calculus, the definition of the derivative, and he even started talking about integration. Slowly Mabel faded out of his dream, and instead he was in a universe of pure math. Graphs and fractals floated nearby as Dipper excitedly explained the fundamental theorem of calculus.

Slowly, Dipper woke up and found himself in the guest bedroom, with his hands still beneath his pillow. _That dream went in a totally different direction than I expected._ He reached down to readjust his genitals. Sure enough, his underwear was sticky with semen. _I either had a wet dream to my sister, or to calculus, and I don't know which one is worse._

The clock on the side of the bed said it was five thirty in the morning, and Dipper had a bad headache. _I wonder if this is what a hangover feels like._ Dipper decided it was still too early to get up so he tried to get back to bed.

Dipper was once again back in the classroom with his sister, who was wearing only her pink panties. Dipper himself was clad only in his boxers.

"Now," said Dipper. "Where were we?"

"You were just explaining to me calculus." Mabel said excitedly.

"No, I mean before that."

"Oh, I was totally going to bone you broski. But now we don't have time, class is about to start."

Suddenly Mabel was fully clothed, Dipper was fully naked, and people were starting to stream in through the door. Dipper started to panic and said, "Mabel, where are my clothes?"

She looked around, but couldn't find any, and shrugged. Dipper ran out of the classroom and out the front door and right into his parents.

Dipper woke up screaming. He looked back over to the clock, it said six thirty in the morning, an hour had passed. _Maybe it isn't too early to get up now._ Dipper rolled out of bed, and went to take a shower.


End file.
